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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0056-serial-tegra-Use-port-lock-wrappers.patch | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/debian/patches-rt/0056-serial-tegra-Use-port-lock-wrappers.patch b/debian/patches-rt/0056-serial-tegra-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..f53b521dc --- /dev/null +++ b/debian/patches-rt/0056-serial-tegra-Use-port-lock-wrappers.patch @@ -0,0 +1,176 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:13 +0206 +Subject: [PATCH 056/134] serial: tegra: Use port lock wrappers +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +When a serial port is used for kernel console output, then all +modifications to the UART registers which are done from other contexts, +e.g. getty, termios, are interference points for the kernel console. + +So far this has been ignored and the printk output is based on the +principle of hope. The rework of the console infrastructure which aims to +support threaded and atomic consoles, requires to mark sections which +modify the UART registers as unsafe. This allows the atomic write function +to make informed decisions and eventually to restore operational state. It +also allows to prevent the regular UART code from modifying UART registers +while printk output is in progress. + +All modifications of UART registers are guarded by the UART port lock, +which provides an obvious synchronization point with the console +infrastructure. + +To avoid adding this functionality to all UART drivers, wrap the +spin_[un]lock*() invocations for uart_port::lock into helper functions +which just contain the spin_[un]lock*() invocations for now. In a +subsequent step these helpers will gain the console synchronization +mechanisms. + +Converted with coccinelle. No functional change. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Signed-off-by: John Ogness <john.ogness@linutronix.de> +Link: https://lore.kernel.org/r/20230914183831.587273-57-john.ogness@linutronix.de +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/tty/serial/serial-tegra.c | 32 ++++++++++++++++---------------- + 1 file changed, 16 insertions(+), 16 deletions(-) + +--- a/drivers/tty/serial/serial-tegra.c ++++ b/drivers/tty/serial/serial-tegra.c +@@ -411,7 +411,7 @@ static int tegra_set_baudrate(struct teg + divisor = DIV_ROUND_CLOSEST(rate, baud * 16); + } + +- spin_lock_irqsave(&tup->uport.lock, flags); ++ uart_port_lock_irqsave(&tup->uport, &flags); + lcr = tup->lcr_shadow; + lcr |= UART_LCR_DLAB; + tegra_uart_write(tup, lcr, UART_LCR); +@@ -424,7 +424,7 @@ static int tegra_set_baudrate(struct teg + + /* Dummy read to ensure the write is posted */ + tegra_uart_read(tup, UART_SCR); +- spin_unlock_irqrestore(&tup->uport.lock, flags); ++ uart_port_unlock_irqrestore(&tup->uport, flags); + + tup->current_baud = baud; + +@@ -522,13 +522,13 @@ static void tegra_uart_tx_dma_complete(v + dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state); + count = tup->tx_bytes_requested - state.residue; + async_tx_ack(tup->tx_dma_desc); +- spin_lock_irqsave(&tup->uport.lock, flags); ++ uart_port_lock_irqsave(&tup->uport, &flags); + uart_xmit_advance(&tup->uport, count); + tup->tx_in_progress = 0; + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&tup->uport); + tegra_uart_start_next_tx(tup); +- spin_unlock_irqrestore(&tup->uport.lock, flags); ++ uart_port_unlock_irqrestore(&tup->uport, flags); + } + + static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup, +@@ -598,13 +598,13 @@ static unsigned int tegra_uart_tx_empty( + unsigned int ret = 0; + unsigned long flags; + +- spin_lock_irqsave(&u->lock, flags); ++ uart_port_lock_irqsave(u, &flags); + if (!tup->tx_in_progress) { + unsigned long lsr = tegra_uart_read(tup, UART_LSR); + if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS) + ret = TIOCSER_TEMT; + } +- spin_unlock_irqrestore(&u->lock, flags); ++ uart_port_unlock_irqrestore(u, flags); + return ret; + } + +@@ -727,7 +727,7 @@ static void tegra_uart_rx_dma_complete(v + struct dma_tx_state state; + enum dma_status status; + +- spin_lock_irqsave(&u->lock, flags); ++ uart_port_lock_irqsave(u, &flags); + + status = dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); + +@@ -749,7 +749,7 @@ static void tegra_uart_rx_dma_complete(v + set_rts(tup, true); + + done: +- spin_unlock_irqrestore(&u->lock, flags); ++ uart_port_unlock_irqrestore(u, flags); + } + + static void tegra_uart_terminate_rx_dma(struct tegra_uart_port *tup) +@@ -836,7 +836,7 @@ static irqreturn_t tegra_uart_isr(int ir + bool is_rx_int = false; + unsigned long flags; + +- spin_lock_irqsave(&u->lock, flags); ++ uart_port_lock_irqsave(u, &flags); + while (1) { + iir = tegra_uart_read(tup, UART_IIR); + if (iir & UART_IIR_NO_INT) { +@@ -852,7 +852,7 @@ static irqreturn_t tegra_uart_isr(int ir + } else if (is_rx_start) { + tegra_uart_start_rx_dma(tup); + } +- spin_unlock_irqrestore(&u->lock, flags); ++ uart_port_unlock_irqrestore(u, flags); + return IRQ_HANDLED; + } + +@@ -969,11 +969,11 @@ static void tegra_uart_hw_deinit(struct + } + } + +- spin_lock_irqsave(&tup->uport.lock, flags); ++ uart_port_lock_irqsave(&tup->uport, &flags); + /* Reset the Rx and Tx FIFOs */ + tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR); + tup->current_baud = 0; +- spin_unlock_irqrestore(&tup->uport.lock, flags); ++ uart_port_unlock_irqrestore(&tup->uport, flags); + + tup->rx_in_progress = 0; + tup->tx_in_progress = 0; +@@ -1292,7 +1292,7 @@ static void tegra_uart_set_termios(struc + int ret; + + max_divider *= 16; +- spin_lock_irqsave(&u->lock, flags); ++ uart_port_lock_irqsave(u, &flags); + + /* Changing configuration, it is safe to stop any rx now */ + if (tup->rts_active) +@@ -1341,7 +1341,7 @@ static void tegra_uart_set_termios(struc + baud = uart_get_baud_rate(u, termios, oldtermios, + parent_clk_rate/max_divider, + parent_clk_rate/16); +- spin_unlock_irqrestore(&u->lock, flags); ++ uart_port_unlock_irqrestore(u, flags); + ret = tegra_set_baudrate(tup, baud); + if (ret < 0) { + dev_err(tup->uport.dev, "Failed to set baud rate\n"); +@@ -1349,7 +1349,7 @@ static void tegra_uart_set_termios(struc + } + if (tty_termios_baud_rate(termios)) + tty_termios_encode_baud_rate(termios, baud, baud); +- spin_lock_irqsave(&u->lock, flags); ++ uart_port_lock_irqsave(u, &flags); + + /* Flow control */ + if (termios->c_cflag & CRTSCTS) { +@@ -1382,7 +1382,7 @@ static void tegra_uart_set_termios(struc + if (termios->c_iflag & IGNBRK) + tup->uport.ignore_status_mask |= UART_LSR_BI; + +- spin_unlock_irqrestore(&u->lock, flags); ++ uart_port_unlock_irqrestore(u, flags); + } + + static const char *tegra_uart_type(struct uart_port *u) |